The present study was intended to provide perspective, albeit less than unequivocal, on the research of Lynn (2010) who reported higher IQs in the northern than southern Italian regions. He attributes this to northern Italians having a greater genetic similarity to middle Europeans and southern Italians to Mediterranean people. Higher regional IQ…

Beraldo (2010) and Cornoldi, Belacchi, Giofre, Martini, and Tressoldi (2010) (CBGMT) have eight criticisms of my paper (Lynn, 2010) claiming that the large north-south differences in per capita income in Italy are attributable to differences in the average levels of intelligence in the populations. CBGMT give results for seven data sets for IQs in…

Working with data from the PISA study (OECD, 2007), Lynn (2010) has argued that individuals from South Italy average an IQ approximately 10 points lower than individuals from North Italy, and has gone on to put forward a series of conclusions on the relationship between average IQ, latitude, average stature, income, etc. The present paper…

Sex differences on the Dutch WISC-R were examined in Dutch children (350 boys, 387 girls, age 11-13 years) and Belgian children (370 boys, 391 girls, age 9.5-13 years). Multi-group covariance and means structure analysis was used to establish whether the WISC-R was measurement invariant across sex, and whether sex differences on the level of the…

Because no single characteristic defines intelligence, there can be no adequate process-based definition of intelligence. In principle, a combination of many empirically derived measures into a single index, as in a Binet test, would be appropriate. In practice, many of the relevant characteristics are simply impossible to measure. (Author/RD)

Taylor (1980) claims to show that the similarity in IQ between monozygotic twins reared apart found in prior studies is due to similarity in their environments. A reanalysis using Taylor's classification of environments but an alternative IQ measure shows that his findings do not constructively replicate. (Author/RD)

The impetus for our study was the contention of both Lynn [Lynn, R. (1991) "Race differences in intelligence: A global perspective." "Mankind Quarterly," 31, 255-296] and Rushton [Rushton, J. P. (1995). "Race, evolution and behavior: A life history perspective." New Brunswick, NJ: "Transaction"; Rushton, J.…

The question of how to integrate developmental (Piagetian) and psychometric conceptions and assessments of intelligence is considered. A solution which incorporates the contributions of each position--intelligence as forms and as traits--is offered. Premises and objectives of each tradition are reviewed and compared. Overlaps make synthesis…

The purpose of this study is threefold. First, an estimate of state IQ is derived and its strengths and limitations are considered. To that end, an indicator of downward bias in estimating state IQ is provided. Two preliminary causal models are offered that predict state IQ. These models were found to be highly predictive of state IQ, yielding…

It is unclear whether brain mechanisms underlying human intelligence are distributed throughout the brain or mainly concentrated in the frontal lobes. Data are inconsistent possibly due, at least in part, to the different ways the construct of intelligence is measured. Here we apply the method of correlated vectors to determine how the general…

A number of studies in the United States have found that Jews obtain higher average IQs than white gentiles. This paper examines whether this is also the case in Britain. Three early studies are summarized that found that Jews in Britain have mean IQs in the range of 110-113. New data are presented for two nationally representative samples of 7-16…

We aimed to design alternative estimates of pre-morbid/prior intelligence to the National Adult Reading Test (NART) and the Spot-the-Word (STW) in order to tap non-vocabulary based knowledge stores. The rationale for the development of the new tests was that more cognitively able individuals acquire and retain more "singular facts" from their…

The hypothesis that racial differences in IQ stem from differences in components of executive systems including knowledge base, control processes, and metacognition was investigated. Group differences in metamemory, strategy use, and general knowledge, but not perceptual efficiency, were observed. Metamemory predicted crystallized but not fluid…

Persons representing the extremes of intelligence cannot be included in the same study unless they are approximately equated on mental age, in which case the relative performances of the extreme groups can provide useful information about the nature of intelligence. (Author/RD)

Do stage-related patterns of early cognitive development reported for normally developing children also characterize at-risk and handicapped children when mental age organization of data is used? Mental age predicted Piagetian-based cognitive levels one to three but did not predict highest-level symbolic functioning in 95 handicapped children.…